Locking device for grain dump piston columns



Aug.'1 Z, 1941.. A. P. WINTER 2,252,312 I LOCKING DEVICE FOR GRAIN DUMP PISTON COLUMN S Original Filed May 10, 1938 Patented Aug. 12, 1941 ATET QFFICE LOCKING DEVICE FOR GRAIN DUMP PISTON COLUlWNS August P. Winter, St. Vital, Manitoba, Canada Original application May 10, 1938, Serial No.

207,024. Divided and this application December 12, 1938, Serial No. 245,336

3 Claims.

The invention relates to improvements in looking devices fo grain dump piston columns, the present application being a division application of my prior application Serial No. 207,024, filed May 10, 1938.

An object of the invention is to provide a pneumatically operated, valve controlled, locking device for locking the column in any desired position, the valve being conveniently positioned for manual manipulation by the attendant of the dump.

A further objectis to provide a locking device operated by compressed air which when actuated will positively and automatically lock the rising piston column at a desired point and which is arranged so that the locking bolt thereof will move gradually into locking position, thereby avoiding a direct hammer blow on the column.

A further object is to so mount the locking bolt in the head of the cylinder that the load imposed thereon when locking, will be directly absorbed by the cylinder head.

A further object is to provide a spring for retracting the locking bolt when the air pressure is released from the lock actuating cylinder.

With the above more important objects in view, the invention consists essentially in the arrangement and construction of parts hereinafter more particularly described, reference being had to the accompanying drawing, in which:

Fig. 1 is a vertical longitudinal sectional view centrally through the locking device, certain parts being shown in side elevation and with the looking bolt in the retracted position.

Fig. 2 is a perspective view of the grain dump cylinder and piston column, parts of the piston column and cylinder being broken away.

Fig. 3 is an enlarged internal perspective view of a portion of the cylinder wall.

Fig. 4 is an enlarged perspective view of the locking bolt and a portion of. the shank attached thereto.

In the drawing like characters of reference indicate corresponding parts in the different figures.

It is common practice at the present time to provide the scales in grain elevators with a grain dump for discharging the load from the vehicle being weighed on the scales, and some types of such dumps embody a suspended, vertically disposed cylinder i in which a piston column 2 is slidably mounted, the column rising under the influence of compressed air admitted to the bottom of the cylinder and when rising, carrying with it the front end of the vehicle which isrest- 7 ing on a suitable carrier 3 located at the top end of the piston column.

In carrying out my invention, I provide a cylinder 4 having one end screw threaded into the side of the head 5 of the cylinder I at 6 and the other end thereof provided with a screw cap 1' communicating with a compressed air supply pipe 8 fitted with a manually actuated valve 9.

Within the cylinder 4 is a piston rod or shank Ill having one end supplied with a piston II and associated cup l2, suitably fastened thereto, and the other end extending slidably into a receiving hole or orifice l3 provided in the head of the cylinder l. The latter end of the rod is bent to provide a pintle M on which the locking bolt I5 is pivotally mounted, such bolt being slidably received within a recess I6 formed in the interior wall of the head 5 and opening to the interior of the cylinder.

A coil spring l1 surrounds the end of the piston rod within the cylinder 4 and acts in the well known manner to maintain the locking bolt normally in its out or retracted position as shown in Figure 1.

The piston column 2 is supplied with a lengthwise extending key l8 which passes slidably through a receiving keyway or slot [9 provided in the head 5 and serves to prevent the piston column from rotating in relation to the cylinder. It will here be observed that the locking bolt receiving recess is is wider than the keyway and that the ends I5 of the bolt bear slidably in the guides l6 formed by the ends of the recess which extend to 'the sides of the keyway.

In a desired location, the key is cross notched or cut away at 20 for the purpose of receiving the projected bolt and the notch is so formed that it provides a right angled stop shoulder 2| and an overhanging tapered face 22.

Assuming now that the piston column 2 is in its fully down position, it will be apparent that if one opens the valve 9, compressed air will enter the cylinder 4 and the locking bolt will be held forcibly against the key. Obviously then, upon the piston column rising, under the influence of compressed air admitted to the lower end of the cylinder l, the locking bolt will ride the face of the passing key and will gradually enter the notch due to the tapered face 22 and upon fully entering, will engage the right angled stop shoulder 2| and positively stop the column at the desired position.

By supplying the tapered face, I avoid the bolt striking the column with a damaging hammer-like blow and by having the ends of the bolt sliding in the guide-like ends [6 of the recess, I provide ample bearing surface for the bolt in the cylinder head to absorb the shock occasioned when the bolt engages the shoulder 2|.

Upon air being released from the cylinder l in the well known manner, the piston column will gravitate to its original position under its own Weight and the tapered face 22 will forcibly retract the locking bolt. Subsequently and assuming that the valve 9 is still open, the rising piston column 2 will again be stopped in the same position as previously and upon the air being eX- hausted from the cylinder I, will again gravitate to its original position.

If it is desired that the piston column rise to its full or ultimate height, it is only necessary to release the air from the cylinder 4 and the spring will retract the locking bolt and hold it retracted. Further it will be observed that should the spring fail and air be released from the cylinder 4, the tapered face of the notch will retract the locking bolt and it will remain retracted until air is admitted again to the latter cylinder.

I wish it to be particularly noted that the locking bolt is operated by compressed air and that accordingly, a locking bolt so operated could be utilized to advantage to lock the piston column to the cylinder head in any position of the piston column. The details of the notch formation would then, of course, be designed to accommodate the particular requirements.

What I claim} as my invention is:

ii. In a grain dump the combination with a cylinder, a piston column endwise slidable therewithin and a lengthwise extending key secured to the column and slidably received within a keyway associated with the cylinder, of a stop member associated with the cylinder and adapted to enter a notch provided in the key and prevent further rising movement of the column and valve controlled means operated by compressed air for projecting said member forcibly into contact with the key, said notch presenting a right angled shoulder at its under side and an overhanging sloping face thereabove.

2. In a grain dump the combination with the head of a cylinder, a piston column endwise movable therewithin and a key secured to and extending lengthwise of the column and slidably received within a keyway provided in the head, of a stop bolt slidably mounted in the head of the cylinder, a piston associated with the bolt and a cylinder carried by the head and slidably receiving the latter piston and communicating with a valve controlled source of compressed air supply, said key being provided with a cross notch for the bolt, presenting a right angled under shoulder and an overhanging tapered face.

3. In a grain dump the combination with a cylinder, a piston column endwise slidable therewithin and a lengthwise extending key secured to the column and slidably received within a keyway associated with the cylinder, of a stop member associated with the cylinder and adapted to enter a notch provided in the key and prevent further rising movement of the column and valve controlled means operated by compressed air for projecting said member forcibly into contact with the key, said notch having a stop engaging shoulder on its underside and a stop ejecting face thereabove.

AUGUST P. WINTER. 

